1. Field of the Invention
The present invention relates to motor vehicles and in particular to a gear operated shut valve for a ventilation system.
2. Description of Related Art
Methods of stopping airflow in a ventilation system for a motor vehicle have been previously proposed. Bauer (U.S. Pat. No. 4,656,926) is directed to a ventilation control unit for motor vehicles. Bauer teaches a control unit with multiple knobs. The knobs may be used to control heating, air conditioning or ventilation systems.
Bauer teaches a plurality of rotatable control knobs that are mounted to a front panel. The control knobs are directly connected to bevel gears. The bevel gears are further connected to driven bevel gears. The gears are oriented at a ninety degree angle from one another. As the driven bevel gears rotate, adjusting levers are moved, which further move the Bowden cables. Bauer teaches that it is possible to operate a fan flap with these Bowden cables.
Demerath (U.S. Pat. No. 6,533,655) is directed to an air vent for ventilation systems. Demerath teaches an operating element that can be used to manually adjust air guiding vanes, as well as an airflow flap. The position of the airflow flap can be adjusted, and includes a position to completely block the airflow to the air vent.
Demerath teaches an operating knob disposed outside of the vent that may be rotated, which causes a rotation in a cardan shaft. As the cardan shaft is rotated, a first conical wheel gear of a bevel gear also rotates. The bevel gear is meshed with a conical gear wheel that is attached to an airflow flap. Therefore, as the bevel gear rotates, the setting angle of the airflow flap is changed. As the setting angle of the airflow flap is changed, the airflow through the vent is varied, and in some cases the airflow flap can be positioned to block the flow of air completely.
The Bauer and Demerath designs require the airflow flap or the fan flap to be disposed behind the vent. Furthermore, the Bauer design requires the use of Bowden cables in addition to gears. Demerath also requires the use of a cardan shaft. There is a need in the art for a system and method that addresses the shortcomings of the prior art listed above.